TW589290B - Formed SiC product and manufacturing method thereof - Google Patents

Abstract

A formed SiC product having low degree of light transmittance useful in a variety of heat resistant components such as equalizing rings, dummy wafers, and other components employed in semiconductor manufacturing facilities, and the manufacturing method thereof. The product is a CVD-formed SiC product prepared by growing a coating on a substrate with a CVD process and thereafter removing the substrate. The product is characterized by having at least one SiC layer with different grain characteristics located either on its surface or within the main structure, and having a light transmittance rate of 0.4% or less for the wavelength range from 300 to 2,500 nm, and 2.5% or less for the wavelength range exceeding 2,500 nm. The method for manufacturing the said formed SiC product is characterized by forming at least one SiC layer with different grain characteristics either on its surface or within the main structure provided by changing the CVD reaction conditions.

Description

589290

The present invention relates to a SiC formation and development, and good thermal resistance and mechanical strength, especially 'is it right? The molded body has high purity, which makes it suitable for different thermal resistance components. It has a very low transmittance. The principle he uses in semiconductor manufacturing equipment = material two equalization rings and (du: two fer) and Others are used in diffusion furnaces and etching equipment: = and other methods similar to c = in semiconductor manufacturing equipment to manufacture the Sic formed body. This Maoyue also talked about the good material properties of Sic Silicon Reverse Silicon (Sic), such as thermal resistance, corrosion resistance and mechanical strength, so it is beneficial to be used as a material in different industrial applications. In particular, a sic formed body (hence the name "CVD-SiC formed body") manufactured by the CVD method (that is, chemical vapor deposition method), because of its high density and high purity, is especially used in Applications requiring high purity include applications in a variety of components used to make semiconductors. The CVD-SiC formed body is obtained by allowing a reaction gas to react in a gas phase to deposit S i C crystal grains on a substrate and grow the crystal grains into a film, and then removing the substrate. . The formed body is characterized in that it is a material having high density, high purity, and high structural uniformity. Once chemically deposited in Japanese Patent Application Laid-Open No. 6-2 3 9 6 0 9, a free-standing stone-SiC having an attenuation coefficient of about 2 0 c nr1 or less at 3 # m, and once chemically deposited, Free-standing cold-SiC with an attenuation coefficient of about 20 cm-1 or less at 0.6328 // m is also prepared by the CVD method.

CVD-SiC formed body. Although the CVD-SiC formed body disclosed in the aforementioned publication also has an ideal density of 100% and a metal impurity content of 5 ppm or less and a high purity of 3.5 ppm or less, a CVD-SiC

Page 4 589290 V. Description of the invention (2) It is well known that the shaped body will have a higher light transmittance as the purity increases. Due to the light transmittance, when a CVD-SiC formed body having such a high purity is used in different components of a semiconductor manufacturing equipment, such as a heat treatment device, there may be problems with certain physical properties depending on the application. For example, 'in the semiconductor process, there will be certain process steps including rapid thermal processing (RTP), such as rapid thermal annealing (rapid thermal annealing), rapid thermal cleaning (rapid thermal cleaning), rapid thermal chemical vapor deposition (Rapid thermalchemical vapor

deposition), rapid thermal oxidation, rapid thermal nitridation, and the like. In these manufacturing steps, the use of a SiC formed body as a shielding material has been proposed in order to maintain a good uniform planar characteristic of the wafer substrate when subjected to rapid heating. The 3 i C formed body used as a shielding material must be non-transmissive to heat radiation (Japanese Patent Application Laid-Open No. 9_237 789).

In addition, in an RTP step, when the wafer substrate needs precise temperature control and temperature measurement by a thermometer, when a black body cavity is hot white! When the opposite side of the physical surface is formed, a component (such as providing the substrate of a wafer with the light transmittance of the floor, which will cause unnecessary clutter and disturb the temperature, is described in Japanese Patent Publication No. 8_2558.) A method was developed to form a support ring made of silicon or oxidized to support the wafer substrate and covered with a silicon;

-The column of the branch ring, so that the column is within the range of two: the central material is not polished. The madness is at the detection wave of ten. Furthermore, in order to prevent the light leaking from the heating element from entering the reflection cavity.

Page 5 589290 V. Description of the invention (3) ^ 一 —A method is proposed in Japanese Patent Laid-Open No. 6-34 1 905 to place a partition and a guard ring on the side of the wafer and the ring is The silicon material is made to be colored or gray so that the light energy exuded by the heating element is absorbed. However, the disadvantages of the silicon ^ or silicon-covered module disclosed in JP-A-6-341 905 and JP-A-8-2558 00 are that the acid cleaning performed for repeated use is insufficient, resulting in impermeability. Deterioration of optical characteristics and silicon film thickness. Furthermore, in a plasma etching process, the baffle sheet used to stabilize the wafer etching parameters needs to have a low light transmittance. On the other hand, the gear will be placed on a boat by the operation of an automatic conveyor. Since the shutter is identified by the irradiation of a laser beam, the excessively high transmittance of the shutter will prevent the alpha-hailer from accurately identifying the wafer position, making it difficult to place the shutter at the correct position in the etching device. . The crystal form of a CVD-Si C compact according to the prior art is 10,000 (cubic), and it is yellow and has a light transmittance that is not easily reduced7. An example of a method for reducing the light transmittance is to reduce the light transmittance by using a surface roughening treatment to scatter light on the surface. According to this method, for example, a mirror-finished material with a surface roughness (Ra) of 1 Onm or less will be 40% to 60% under a light wavelength of 900 nm. Light transmittance, but a surface roughening material having a surface roughness of 300 to 5000 nm will have a light transmittance of 0.3% to 08% in the same case. Although this arrangement seems to clearly show a decrease in light transmittance, it does not provide a satisfactory material for a wide range of light. In many cases, it has obtained a good opacity characteristic that can solve the problems of previous art. CVD-SiC molded body

589290

After experiments and observations on the properties 2 and its optical characteristics, the inventor found that if a coating is provided in the material structure of a SiC shaped body to reflect light scattering, its light transmittance can be reduced. s Tianben invention is based on the above findings. Accordingly, one object of the present invention is to provide a SiC shaped body including crystals in the form of high-purity stone. This shaped body has high purity and good thermal resistance and mechanical strength. Light has good non-transmittance, so it is suitable for different components, such as shielding materials, chirped or other components of semiconductor manufacturing equipment. Another object of the present invention is a method 'for producing the CVD-Sic molded body having the above characteristics. The Sic formed body according to the present invention for achieving the above-mentioned object is configured by a CVD process. The formed body includes at least one 31 (: layer with different grain characteristics and two located on its surface or in the main structure. There is a light transmittance of 0.4% or less in the wavelength range from 2500 nm and a light transmittance of 2.5% or less in the wavelength range above 2500 nm. The method for manufacturing a Si C shaped body according to the present invention includes a process for manufacturing a CVD-SiC shaped body by growing a sic layer on a graphite substrate by CVD and then removing the hafnium substrate, In a surface or main structure of a CVD-siC formed body formed by changing a CVD reaction condition on a graphite substrate " surface, at least one S i C layer having different grain characteristics is formed and subsequently removed Substrate. Another method for manufacturing a SiC formed body according to the present invention includes using a CVD obtained by growing a Sic film by CVD on a surface of a graphite substrate and then removing the substrate. -SiC formed body as a substrate; and a method for changing CVD reaction conditions On the surface or main knot of the substrate

Page 7 589290

Yes, Wang's s 1 (J layer V. Invention description (5)) forms at least one structure without a simple illustration [Figure 1 is a schematic flow chart describing a method for manufacturing a sic shape according to the present invention. 2. FIG. 2 is a schematic flowchart describing another method for manufacturing a siC formed body according to the present invention. FIG. 3 is a diagram showing the relationship between the wavelength of light waves and the transmittance in Embodiment 2. FIG. 4 is the wavelength of light waves in Embodiment 3 and Relationship between light transmittance. Fig. 5 is a relationship between light wave wavelength and light transmittance in a comparative example.

[Example] A SiC formed body according to the present invention is a cVD-SiC formed body, which is prepared by first depositing a SiC film on a substrate by a CVD method and then removing the substrate and then A surface or main structure having at least one SiC layer with different grain characteristics.

When SiC is deposited on the surface of a substrate and a sic film is formed, the reaction gas first reacts in the gas phase to generate a 3 丨 (nucleus) on the surface of the substrate. Subsequently, the S1 C nuclei grow into amorphous s 丨 c, Then through the formation of fine polycrystalline s 丨 c grains, it further grows into a crystalline structure with columnar arrangement to form a SiC film. Therefore, the characteristics of a CVD-SiC formed body, such as mechanical strength, thermal characteristics, Optical characteristics, etc., will vary with the grain characteristics of the SiC film deposited and formed on the substrate surface. For example, when light passes from a Sic layer with a larger average grain diameter through an average crystal When the si C layer has a smaller particle diameter, complex reactions such as scattering, refraction, and reflection occur at the interface to reduce light transmission. Similarly, when

Page 8 589290 V. Description of the invention (6) When light passes from a SiC layer with a smaller average grain diameter to a SiC layer with a larger average grain diameter, the light transmittance is reduced for the same reason. The si C formed body of the present invention obtains a low light transmittance by providing a Si c layer with different grain characteristics on its surface or in the main structure, so it can be produced by the effects of scattering, refraction, and reflection. Adjust its optical characteristics. In other words, it is the use of Sic layers with different grain characteristics to cause confusion in the crystal structure to reduce the light transmittance. It is particularly mentioned that the present invention provides a Sic shaped body with a light transmittance of 104% or less in a wavelength range of 300 to 2500 nra and a wavelength range of 250,000 limbs or more- 2. Transmittance of 5% or less, so that it has a low transmittance in the visible and infrared range. In order to prepare a Sic formed body according to the present invention and deposit the SiC by a CVD process to form a -SiC film, carbon materials, especially graphite materials, can be easily burned by heat treatment in the air. , So it is a better substrate material. Furthermore, among graphite substrates, a material with high purity, uniformity and minimum impurity content is preferred. There are several ways to remove the graphite base # after the SiC 1: layer is grown, including machine cutting, grinding, heating in air, or any feasible mixing method. In the above method, because of the simplicity of operation, it is preferable to remove the stone black substrate by burning. i ”—CVD_SlC compacts are manufactured by first depositing Sic on a graphite substrate surface using a CVD process, then coating a Sic layer, then growing into a SiC film before removing the graphite substrate. SiC film formation It is obtained through the following procedure. A graphite substrate is placed in a CVD apparatus.

589290

Through the way of extracting air, heating and filling with hydrogen, the air is replaced, and the pressure is lifted to hydrogen. Then, using hydrogen as a carrier gas, halogen halide compounds such as trichloromethylsilicon 70, dichlorobenzylsilane, dichlorofluorenylsilane, and trichlorodimethylsilane are charged into the system as a reaction gas. A gas phase thermal separation reaction is initiated to deposit SiC on a graphite substrate and coat a SiC layer thereon.

During the growth of the SlC film, the reaction gas first enters the gas phase: it reacts to produce a SiC core on the graphite substrate. The SiC core then grows into non-junction S 丨 C 'and then gradually grows into fine polycrystalline SiC grains. As the c VD reaction continues, the fine polycrystalline SiC grains will further grow into a circle, arranged = crystalline structure to form a s 丨 c coating. Since the sic thus formed is a film containing SiC grains with a cylindrically arranged crystalline structure, the characteristics of the CVD-SiC composition, such as mechanical strength, thermal characteristics, and optical characteristics, will vary with the characteristics of the Si C grains. There are different. The characteristics of the SiC crystal grains that form the SiC film can be changed by changing the CVD reaction f-piece. For example, it can be deposited by appropriately changing the mixing ratio of reaction gas-organized silicon compound) and reducing agent (hydrogen), the mixed gas, the flow rate, the reaction temperature or reaction time of CVD, and the pressure conditions of the CVD reaction device. It is used to form SiC grains with different characteristics. During the growth of the Sic film, the setting of the above CVD reaction conditions can be appropriately changed to form at least one Sic layer with different grain characteristics on the surface or main junction of the CVD-Si c formed body. For example, as shown in Figure 1 · First show the cvd reaction for a certain period of time under the required CVD reaction conditions-to form a SiC film of a CVD-SiC formed body, and then at a lower reaction temperature

Page 10 589290 V. Description of the invention (8) The CVD reaction is carried out for a certain period of time and then a CVD reaction under another original condition is performed. In the CVD-SiC formed body, a different grain characteristic, average Si C layer with smaller grain size. Thus, the CVD-SiC formed body according to the present invention is prepared after the graphite substrate is removed. Two or more Si C layers with different grain characteristics can be made by repeatedly using similar procedures.

On the other hand, as shown in Fig. 2, a s i C shaped body according to the present invention can also be made using one of the following different methods. First, a SiC layer is formed on the surface of a graphite substrate by a CVD reaction. This process is performed for a certain period of time under the CVD reaction conditions required to form a SiC film of a CVD-SiC compact. Next, the graphite substrate was removed, and the CVD-SiC formed body was used as a substrate to perform a CVD reaction at different reaction temperatures to form a SiC layer having a different average grain size. The SiC formed body thus produced has a density of 3.2 g / cm3 or more, a thermal conductivity of 220 W / niK or more, and a thermal expansion coefficient of 3.5 to 4.2 X10-VK

(From room temperature to 100 ° C). They are stable even after being irradiated with a high energy light and have a low metal impurity content of j xlO1 Gatom / cm2 or less as measured by a total reflection X-ray fluorescence analysis. Therefore, this SiC

In addition to the good thermal resistance or mechanical strength of the molded body, it also has properties of high purity and low light transmittance. The present invention can be explained in more detail in the following implementation examples and comparative examples: Example 1 will be a uniform graphite material having a bulk density of 1.8 g / cm3, a thermal expansion coefficient of 3.9x10-6 / k, and an ash content of 20pPm. Machined to a diameter

589290 V. Description of the invention (9) 2 0 2mm, 5mm thick disc. This graphite substrate was then placed in a quartz reactor of a CVD reactor. After replacing air with hydrogen, a mixed gas containing reaction gas-trichloromethyl and carrier gas-hydrogen was charged into the reaction furnace at a rate of 190 liters per minute, where the volume concentration of trichloromethylalkane was 7.5 percent. The CVD reaction was first performed at a reaction temperature of 1 400 ° C for 12 hours, and then at 1100 ° C for 1 hour to form a SiC film with a grain diameter of 1.5 // m, and finally at 1 40 The formation of the entire S i C film was carried out at 0 ° C for 12 hours. Then, the graphite substrate was burned in the air 'and the final formed body was ground to obtain a dish-shaped SiC formed body having a diameter of 200 mm and a thickness of 0.5 mm. The second embodiment is a Si C molded body manufactured by the same method as in the first embodiment, in which the CVD reaction is first performed at a reaction temperature of 1 400 ° C for 12 hours, and then a lower reaction temperature 1 2 0 0 ° C for 1 hour to form a SiC film with a grain size of 2.1 1 // m, and then 7 hours at 1 40 0 ° C and then 1 at 1 200 ° C Hours and 8 hours at the original 1 400 ° C to complete the formation of the entire Si C film. Example 3 is a Si C molded body manufactured in the same manner as in Example 1. The CVD reaction is performed at a reaction temperature of 1 400 ° C for 24 hours, and then at a lower reaction temperature. Performed at 110 ° C for 1 hour. The comparative example is a Si C molded body manufactured by the same method as in Example 1. The CVD reaction is performed first at a reaction temperature of 1 400 ° C for 25 hours.

Page 12 589290

In the wavelength range of 300 to 2500 nm, the light transmittance is between 0.1 and 0.4%. When the wavelength range is 2500 to 3200 nm, the light transmittance is between 1.8 and 2.0%. As described above, according to the present invention, since a si C layer having at least one different grain characteristic can be formed on the surface or main structure of a Sic shaped body, the light transmittance can be reduced, so it has high purity, high density, and good opacity S i C shaped bodies having properties, thermal resistance and mechanical strength may exist. In addition, according to the manufacturing method of the present invention, a Sic shaped body having a low light transmission property can be easily manufactured by changing the reaction conditions of CVD. Therefore, the S i C formed body according to the present invention is suitable for different thermal resistance components (such as shielding materials, equalizing rings and other semiconductor manufacturing heat treatment devices), or baffles and other semiconductors in diffusion furnaces, etching devices, CVD devices, etc. The application of manufacturing equipment components is very effective.

Claims (1)

589 ^ 0 _r! 卜 一一 1ην # .. Ί 丨 ~ 1 tl ^ l〇l578r — you v_: ry / 士 说 射 又 六 、 Applicants for patents ® Two ......... ,, ..... 1 --- 1 · A 々-shaped CVD-Sic shaped body containing Sic particles, prepared by a CVD process, the shaped body includes an average particle diameter on the surface or in the main junction of 1.5 ~ 2 · 1 // m and an Sl layer with an average particle diameter that is different from the adjacent Sic layer (including one and has an average particle diameter that is larger or smaller than the average particle diameter of the adjacent SiC layer), and has a wavelength range: A light transmittance of 0.4% or less and a light transmittance of 2.5% or less at a wavelength range greater than 250 nm. 2 · A method for manufacturing a CVD-SiC formed body, by It is manufactured by growing a SiC film by CVD on a carbon substrate and then removing the substrate, and is characterized in that: on the surface of the 々-shaped CVD-Sic formed body formed on the surface of the carbon substrate Or in the main structure, at least one Sic layer with different average particle diameter is formed by changing the reaction temperature of the cv D, and then the substrate is removed. 3. A SiC forming The manufacturing method includes the use of a multi-type substrate obtained by growing a one-point Sic film by CVD on a surface of a carbon substrate and then removing the substrate. Is a substrate; and in the surface or main structure of the substrate, at least one Si (:) layer having a different average particle diameter is formed by changing the reaction conditions of the CVD. 2l22-2427-pf3.ptc Page 15 2004.01.16.017